Incosistent results from engine power limiter.

  • Thread starter Aloha62_2
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1,116
United Kingdom
England
Unsure if this is a one off specific to this one car in one state of tune or a wider issue.

I spent a fair bit of time today developing a mini suitable for a race group with friends , a one class race using the 1998 mini cooper limited to 700kg and 105bhp. Two of us myself included used to own and run a race mini hence the unconventional choice.

I tuned the mini up to ~90bhp and was able to hit around 115mph on the high speed ring straight, this was with gearing that was not optimized. I then purchased a stage 1 turbo which put the power at ~125bhp and used the power limiter to drop the bhp down to 105bhp, end result acceleration died and top speed capped out at about 110mph. confused I figured the power band was wrong for the car so I dropped the turbo and used the stage 2 engine upgrade instead, similar power boost and again dropped it down to 105bhp, same result: the car was much slower then the original ~90bhp setting. Took the power limiter off and the car launched down the straight and was bouncing off 130mph.

So despite having over 10% power gain the car was considerably slower.

Anyone experienced similar?
 
The results may be due to the power band and how the power limiter affects it.

Depending on how the engine is built it may be making most of its power at fairly low rpm and have a dramatic drop off after peak power before the redline. The GT games favor high reving engines that make peak power close to redline.
Using the power limiter to restrict power can make the situation even worse. Using more than about 5% will have your torque dropping even faster after peak.

I'd suggest for your Mini that you try building the engine to as close to the 105HP limit as you can so you need use as little power limiter as possible.

Also if your manual shifting work on setting your transmission to keep you near the peak of your power band as much as possible.
 
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